There is a need for measurement of resistance in the range of μΩ-mΩ of any high voltage environment object, such as circuit breakers, bus bars, contacts, joints, ground grids etc. based on temporary high current generation.
One way of achieving such measurement is to generate and apply a high current, more than 100 Amperes and preferably more than 250 Amperes during a short time (a few seconds and preferably less than two seconds) to measure extremely low resistances from less than 1 μΩ to 20 mΩ as a static value (Static Resistance Measurement—SRM) or as a high frequency sampled time series (Dynamic Resistance Measurement—DRM) for evaluation of arcing contact length, contact timing, corrosion or otherwise caused increase of resistance in circuit breaker contacts, bus bars and joints for the diagnosis of quality, such as if the product is conformant with product specification, on new objects and the need for maintenance on installed equipment. Having a high current is important for achieving high resolution and reliability in the DRM measurement. The measured voltage across the circuit breaker is proportional to the current through the very low resistance, according to Ohm's law. The higher the current, the better resolution.
Conventional prior art measuring devices are bulky and heavy due to the batteries or accumulators, often lead batteries, provided in the device for providing the high current required for accurate measurement.
Thus, it would be advantageous if a light weight measuring device could be provided, which also could sustain essentially continuous operation without requiring long time battery recharging.